 ;; TODO: smarter choose-leaf?
 ;; TODO: conspiracy number, weighted, etc.
 ;; TODO: forcing summary of TS in summary_graphs makes a lot of extra comps (lefts), doesn't help.
+;; TODO: propagate across subsumption links? (must be careful here, not to cross state/plan syntax/semantics line)
 
 ;;;;; SP caching
 ;; TODO: tail (i.e., pair) caching? -- Only help for >2 len refs...

;; TODO: more generic propagation?  (We know: names, subs. relationships on sets.  Efficient lookups?)
;; TODO: children wait on one (or more) subsumption parents.


;;;;; Pessimistic
;; TODO: add pessimistic variants (shared primitives)
;; TODO: bounding pressimistic descritpions (assume consistency for now)
;; TODO: hook up pess/opt with same input set?
;; TODO: pruning. 

;;;;; Tree construction
;; TODO: smarter output-collector (semantic) -- problems here though.
;; TODO: don't always split-left?
;; TODO: don't release children until they have lower reward or are primitive? 
;; TODO: make sure dead stuff can be GC'd
;; TODO: alternative child release strategies, e.g. wait 'til solved

;;;;; Summaries and solving 
;; TODO: lazy/pseudo-solve (regular seems impossible; bounds mean apparent decrease may be increase.

;; Can be implemented by not letting children go until they have subs...
;;  (and not incorporating into summary, except as bound) .... ?


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;       Options      ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
